Avro 549 Aldershot

Aldershot

Manufacturer: Avro
First flight: 1921
Introduced: 1924
Retired: 1925
Status: Retired
Primary user: Royal Air Force
Produced: 17
Variants: Avro Andover

The Avro 549 Aldershot was a British single-engined bomber aircraft built by Avro.

Development and design

The Aldershot was designed to meet the 1920 British Specification 2/20 for a long-range day and night bomber to be powered by a Rolls-Royce Condor engine. The specification required a range of 500 miles (800 km) and a bombload of 2,000 lb (900 kg), originally comprising a single World War I vintage 1,800 lb (820 kg) SN bomb, but then changed to four 500 lb (230 kg) bombs carried externally or eight 250 lb (114 kg) bombs internally. The Air Ministry gave Avro a contract for two prototypes, designated Aldershot I, on 2 December 1920, in competition with the de Havilland Derby.

The first prototype flew at Hamble Aerodrome near Southampton in October 1921. As a result of test flying, the fuselage was lengthened by 6 ft (2 m)in order to improve directional control, being displayed in this form at the RAF Display at Hendon on 24 June, the second prototype flying in July, with the lengthened fuselage and a modified undercarriage.

The first prototype was modified as a testbed for the water-cooled Napier Cub engine, in this form becoming the Aldershot II, flying on 15 December 1922. It was later used to test the slow-revving 850 hp (630 kW) Beardmore Typhoon I inline engine, flying in this form on 10 January 1927.

The Aldershot was a three-bay biplane, with a steel framed fuselage structure with plywood and fabric covering, and wooden wings. The pilot and navigator were seated side-by side in a cockpit behind the upper wing trailing edge, with additional accommodation for the navigator, who was also the bomb-aimer in a cabin inside the fuselage, which was provided with four circular windows on each side. A gunner sat in a separate cockpit behind the pilot, and was armed with a Lewis gun on a Scarff ring. Another Lewis gun could be fitted to a ventral mounting in the cabin, while there was provision for a fixed, forward firing Vickers machine gun operated by the pilot, although this was rarely fitted. A bomb-bay forward of the cabin could hold eight 250 lb (114 kg) bombs, with larger bombs being carried externally under the fuselage.

The Aldershot also formed the Basis for the Avro Andover transport, which used the same wings, tail and power plant but had a new fuselage.

Operational history

When it was evaluated against the Derby, the Aldershot proved superior to the de Havilland bomber, with the mixed construction Aldershot being about 800 lb (360 kg) lighter than the all-wooden Derby, which had no provision for carrying its bombload internally, or for any ventral armament.

On 26 January 1923, the Air Ministry ordered 15 aircraft under the designation Aldershot III. The only operator of the aircraft was No. 99 Squadron RAF which reformed on 1 April 1924, receiving its Aldershots from July that year. The Aldershot was mainly used for night flying, but occasionally flew day bombing exercises. Unlike the other members of the RAF's heavy bomber force, it was operated in an all-silver colour sceme, rather than the dark-green NIVO scheme usually used for night operations. By 1925, the Air Ministry had decided that heavy bombers should have multiple engines, and 99 Squadron started to receive the twin-engined Handley Page Hyderabad in January 1926, with the Aldershots being completely replaced in Squadron service by March that year.

Variants

Avro 549 Aldershot I
Prototype. Two built.
Avro 549A Aldershot II
First prototype modified with 1,000 hp (746 kW) Napier Cub engine.
Avro 549B Aldershot III
Production version. 15 built. One modified with metal wings as Avro 549M.
Avro 549C Aldershot IV
First prototype modified with Beardmore Typhoon engine.

Operators

United Kingdom

Royal Air Force
No. 99 Squadron RAF

Specifications (Aldershot III)

Data from Avro Aircraft since 1908

General characteristics

Crew: 3
Length: 45 ft 0 in (13.72 m)
Wingspan: 68 ft 0 in (20.73 m)
Height: 15 ft 3 in (4.65 m)
Wing area: 1,064 ft² (98.9 m²)
Empty weight: 6,310 lb (2,868 kg)
Max takeoff weight: 10,950 lb (4,977 kg)
Powerplant: 1x— Rolls Royce Condor III, 650 hp (485 kW)

Performance

Maximum speed: 110 mph (96 knots, 177 km/h)
Cruise speed: 92 mph (80 knots, 148 km/h)
Range: 625 mi (1,006 km)
Service ceiling: 14,500 ft (4,420 m)

Armament

Guns: 1 x— .303 in (7.7 mm) Lewis Gun in rear cockpit, provision for 1x— Lewis gun in ventral position
Bombs: up to 2,000 lb (910 kg) of bombs

Comparable aircraft

de Havilland Derby

Jackson, A.J. (1990). Avro Aircraft since 1908 (Second ed.). London: Putnam. ISBN 0-85177-834-8.
Lewis, Peter (1959). Squadron Histories: R.F.C, R.N.A.S and R.A.F. 1912-59. London: Putnam.
Mason, Francis K. (1994). The British Bomber since 1914. London: Putnam. ISBN 0 85177 861 5.
Jarrett, Philip (March 1993). "By Day and By Night: Part 10 Avro Aldershot Development History". Aeroplane Monthly (London: IPC) 24 (3): pp.8-13, 28. ISSN 0143-7240.
Thetford, Owen (April 1993). "By Day and By Night: Part 11 Avro Aldershot Service History". Aeroplane Monthly (London: IPC) 24 (4): pp.6-10. ISSN 0143-7240.
The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985). Orbis Publishing.

Avro 549 Aldershot Pictures and Avro 549 Aldershot for Sale.

Living Warbirds: The best warbirds DVD series.

Source: WikiPedia